The present disclosure relates to a semiconductor structure and a method of forming the same. More particularly, the present disclosure relates to semiconductor structures including a fuse (E-fuse) that contains at least one underlying tungsten contact for programming and methods of forming the same.
Advanced semiconductor circuitry may use various programmable interconnect elements to connect logic blocks for a number of applications, such as electrically programmable feature selection, speed sorting, die identification, and redundancy implementation. For high-speed applications, the on-state of such structures should have a low resistance. To achieve a high density of such structures in an integrated circuit, the programmable elements should be small.
Programmable fuses are an example of a programmable element, wherein, for example, a fuse element, e.g., sacrificial metal lines buried in a dielectric layer in the circuits (which are normally closed) are blown by vaporizing the fuse element with laser energy to open the circuit that is not selected. Electrically programmable fuses may be used, for example, for chip ID, redundancy, and non-volatile memory programming.
Current electronic fuses may use melting and/or evaporation of material for programming. For example, programmable fuses fall into at least three categories depending on the method of programming. The first category includes laser-blown fuses where the programmable fuses are programmed using a laser to burn or sever the conductive portion of the fuse. The second category includes electrically blown fuses where the fuse is programmed by passing current through it sufficient to overload and open or burn out the fuse. The third category includes electrically blown anti-fuses, where the fuse is programmed with an electric current, which reduces the resistance across the fuse.